Railway traffic controlling system



Aug. 7, 1934. N. c. L. BROWN RAILWAY TRAFFIC CONTROLLING SYSTEM Original Filed Feb. 6, 1929 7 MM ATTORNEY ZZ ZOIZVE 4W Patented Aug. 7, 1934 y 1,969,060 ,g. RAILWAY TRAFFIC coma-011141310; SYSTEM Ned C, L, Brown, Scottsviile, N. Y. assignor to I General Railway'" Signal Company, Rochester,

A i wti n r a 6, 1929,,s na1. No -4 337,826

Renewed November 25, 19 32 16 Claims. 101.246-138) This invention. relates ingeneral to detector track circuits, andhas more particular, reference-tosuch a circuit as .us ed in connection, with a turnout track .switch and a trackbrake type 5 carretarde rand arrangedtQ prevent throwingof thetrack switchundei a car.

In ;classificat icn yards it, is always most desirableto economize inspace, and where a ,car

retarder -,Of;;th$ track brake type vis employed to decrease; the speedof a car before shunting t rou tra k..sw t .-Qn o a t n-o t tra k.

t. s ne es 1 risafe v to; provide a sect of traclgbetween the exit; end of the retarder and the track switch- This track section must elQ eenQush dep nd n on t esn f t r l vinai eo i a d r toeau e uffwie t rberequ r d r e c tetre e se h sec io a l w; t t en t at on. i a swit h m h tre vswitc l .e dt e 0111 for pe a i pletion of theoperation otthe switch nachine, DY.- nsu :t hIQWi switch, e o it is r ach d a e ca -1 switch machine is providedwith avi i s ic mm n ener zin Wi run. through the ironappint of a track relay, to insure that if; .the

the switch machine cannot be i nitiated durin occupancy of the said-track section, y then. this track .sectionmust belong e o 9% t a lun t ng sense, one form ,which the invention C ll. .fls f l l the time of operation of the. switch machine and to respond to the axle shunt producedby occupancy ofsthe track section, torelease.

Unless the track section. between the ,car, re-f tarder and theturn-out switch-belongenough, as. defined, above, the track switch.- can be ener-.

gizedsotardily, (as iorinstance, after occu- I but before releaseof the track relay .as,.;

Fa y; to result, in the track switch being thrown under neath a car.

4 Accordingly, it results-,ircm the abovethat the faster a et -tra k re y slnt e sh r wan safely be the track section referredto, otherthings being equal, .,and hencethegreater the economy in. .space.

It, is usual in classification .yardsto havev alternating current. available and if the track cir--' cuits be energizedfby alternating current and an alternating current track relay be employed, a

track mea s-su h also for the. timerequired for the track relay axles,.. whereby to. economize in yard. pa.ce, as described: above.

With,.the above and other consideration srin mind,- it is proposed,v inv accordance. with ,the presentinvention, toemployein connection; with a switch machine for operating a. track switch spaced some distanceialong the. track-from. .the exit endof a, track brake. type,.of.,car retarder,' a direct current'tractive, or. other, type .track..relay controlling flow of energizingacurrent to. switch machine. .The track relay is.,to..be con- -nected to adetector .trackicircuitcthroughpaf.

rectifier, the track.,circuit.-being supplied-with alternating current from anyconvenientjav'ailablesource; In, this manner the. use. ofrelativelyni expensive alternating currentgrelaysis avoided, and a more rapid responsanfthe trackrelay' to theshunting; effect,.as explainedbelow, of a.

car is obtained. As aresult the turn-Outtrack sw tchcan be safely, located a considerably.

shorter distance from. the. exit end. ofrthe-car retarder than if, an alternating .current-...track relay we1-e .er np1oyed, and therrectifier. omitted.

Further objects, purposes. and. characteristic featuresoi theinvention will appear. as the description progresses, referencebeing hadtowthe I accompanying drawing showing, in a.who11y. diarammatic manner, and not in, any manner in I he single, figure, of drawingirepresents' clia grammatically oneform of, applicants invention.

Referring now .to; the drawing, a. stretch of 1 main track is shown, constituted by track rails 1, with a turn-out track,.,constituted.by track rails 2, controlled by a trackswitchJIS. The track rails 1 are furnished with insulating joints 3 for, defining a detector track section, ;.At.fthe

patent to: iowaNo. .-1 ,605,-, 546. o-..-N.ovember 2,- 1926,;anddncludes an armature 4, a.- field 5, and movable, eontacts (is and 7.; .Which. are .operated ,in usual manner bythe; switch machine tolset ;up; n0r;n ialan d greverse energizing-circuits,

negated at, any convenient point, as asig,

, entrance end to the detector .track. section, travel ,being; the direction-of .the arrow, is arcarrei v is conusual ifornrsuch, for example,. as\shown in..the

nal tower, is a lever L, interlocked with other levers if desired, arranged for manual operation, orautomatic operation as by means of an electric motor energized upon the occurrence of any desired happening, energizing circuits for the switch machine SM. This lever L can be re ciprocated in a usual-manner to move contacts 8 and 9 so as to bridge across fixed contacts 10-11, 1213 or fixed contacts 14-45, 1617 respectively, whereby to control the switch machine, as described in greater detail below.

The lever L is provided-with a lever latch 18 having an actuating coil 19 and a detent 20 for engaging in one or the other of the'locking' .1 trails 1 whereby the alternating current sup-' plied by the secondary of the transformer and to the track circuit of the detector track section operates to energizethe direct current relay TR through its winding 23 when the detector track section is unoccupied v The winding 24 of relay TR can be energized from any source, A. C. or D. C., of electrical energy, as ,for example, a battery B through a contact finger 25 and front point of relay TR, 7

,the battery B. being the source of energy for operating the switch machine SM when proper circuits are completed.

.The usual track relay, when shunted by a car axle, isv slow to release, because the car axle .;'short circuits the relay winding through a very low resistance path, whereby'the speedof decay of flux in the relay core is greatly decreased. With a rectifienisuch as R, inserted asshown, the relay short circuit includes the rectifier, and

;,with a rectifier (as for example a dry plate type of the copper oxide type) having the characteristic of, passing only a negligible current at voltages below a critical value, but a large current 'at'voltages above the critical value, it is seen ggthat constants can be so adjusted as tohavethe usual short circuit of therelay winding become practically an. open circuit. 'In such circumstances, the releaseof the track relay onoccupancy of its block'is very prompt, with a resultant distinct advantage when used in connection with switch. H r

With one dry plate rectifier used, having characteristics. such thatbelow 3 volts practically no a retarder and turn-out track gurrent is passed by the rectifier, but above 3- thereby break the reverse energizing circuit volts a relatively large current is passed, it was foundthat the response of a D. C.'track relay to axle shunting was speeded up from a drop away time of .65 seconds for a D. C. supply, to

,one of .lseconds for an A. C. supply connected to therelay through a rectifier.

A further advantage of this arrangement of alternating current track circuit, rectifier, and D. 0., relay is that it is practical to use a higher i6: .,voltage across the track relay than in the case of D.; C. track circuits. This permits using a much higher resistance in the energizing circuit of athe track relay, eitherintherelay"coil or in other-parts of the circuit'th'an' could be gused in. the caseiof D; 0.,

(low voltage) track circuits. As a result, better shunting of the,

track relay is obtained, and due to the higher resistance in the relay circuit, the flux in the relay coil dies away very quickly and hence the relay releases very quickly. This is because the dying fiux in the-relay coil, induces a Voltage which tends to cause a "flow of current-in a direction to maintain this flux. But due to the high resistance, but little induced current can flow, and hence this fiux dies away very rapidly.

In the drawingis shown a resistance r, in-

' serted in the energizing circuit of relay TR, for

the purposeset forth above, and this resistance can be varied to 'suit the circumstances.

The usual procedure in a classification yard, in connection with classifying cars, is to pass a car through a'retarder as CR, to decrease the speed of the car sufficiently that it can pass through a track switch as TS and take a turnout track as 2. I

Assume now that it is desired to shunt a car from the tracks 1, through the track switch TS- and onto the tracks 2, and that an operator in the signal tower where the control lever L, the

battery B, and the relay TR are all located,

moves the lever to the right as viewed in thedrawing, so as to cause contacts 8 and 9 to bridge contacts 1415, 16-17. If this actuation of lever L takes the detector track ing joints 3, a circuit is completed through switch machine SM for operating track switch TS to reverse or turn-out position, which circuit can be traced as follows: positive side of battery B, contact finger 25 and front point of relay TR, relay winding 24, wire 26, coil 19, wire 27, contacts 15, 8 and 14, reverse wire R, switch machine'contact 7, armature 4, switch machine contact 6, field 5, common wire C, to the negative side of battery B. The section of track between the car retarder CR'and the track switch TS is designed to be long enough to give the switch place prior to occupancy of section defined by the insulat machine sufiicient time to complete its operation and have the track switch TS in the usual manner in reverse position, before the car can reach it.

As soon as the above traced circuit is completed, the coil 19 is energized with the result that the detent 20 engages in notch 22 of lever L and thus prevents return movement of the 3 thrown and locked lever L, (until after the machine has completed its stroke) should the towe'rman', because of a change of mind, or

7 'Thus there is avoided any danger of throwing the switch TS beneath a car due to a change operator.

for any other reason, "attempt 3 to return the lever;

. 1 on the part of the lever Upon the switch machine SM completing its cycle of operation, the movable contacts 6 and 7 are moved to their dotted line positions, to

through the switch machine and at the same time tie-energize the coil 19 to thus permit-de- T tent 18 to drop under the force of gravity and F so as to restore it to conditothe left, as viewed in the at a subsequent time.

unlock the lever .L tion for operation figure of drawing,

Upon the switch machine SM moving its contacts 6 and 7 to the dotted line positions, the

armature and fieldof'the switch machine are connected up in a short circuit, to thereby effectually ,snub the switch machine and bring it.

quickly to a standstill, the

(tilt-detector track section including the rails betacfis '1 :9. and .17, normal wire switch machine contact ,7 in its. dottedlineposition,- and back. to the other: side of armature A. I

r If, thetowerman is tardy in I operatingthe ,lever L,;.a-nd; moves it from its shown. position, to the right, after the detector track circuit isoccupied and; the. quickacting relay TR. has released its contact fingerv 25,;dueto havingits-coil ,23 shunted out -by the; occupying ,-car, the reverse energizing circuit forswitch-machine SM, traced above, is not completed, but is open atcontact finger j 25 r of relay -As a result 1 the switch machine :SM remains ,dewnergized; and all possi-. bilityof throwingjthe track,- switch. under arcar isavoided. V i p 1 if lever L be moved, fromqits, normal. (shown) position, toward .theright so as to 1 complete the reverseenergizing circuit forswitch-machine SM; justprior, to. occupancy ofthe, detector track circuit, and releasepofa relay TR, subsequent occupancy of the detector: track. circuit cannot operate to cause relayiTRtorelease its; contactfinger- 25, since .the reverse-energizing circuitv for the switch .machine, .as. traced: above, includes, the relayriholding .windingi24-in astick circuit including. contact finger: 25.. and front contact of the relay, zivhereby =de-energization of winding 23. does not zde-energizethe relay TR.

-.The1operation. of the'system, when operating the :switchfrom reverse. .to normal, takes place in theus'ame manner asdescribed above, and should not require detailed. explanation.

4 To summarize the operation-of [the system above described,i it .willfibe seen that ;the lever L'must be actuated: prior to release'ofrelay TB in order to initiateIfthe .switch machine, that" if once so "energized, subsequent occupancy. of the detector 2 track. circuit sdoes-not interfere with: the completion. of atheswitch machine ep- 1 eration, that the locking: member 18 for. lever L vqcrevents' the operator 'lfro'mereversinguthe switch -machine in -mid'-stroke, and that this locking means'.18 is released after completion of the. operation-of the switch machine, andla snubbing circuit is -completed'--which quickly current track circuit supplying a direct current track relay through suitable rectifying means, eiiects very desirable economy in yard space and hence constitutes a decided improvement in systems of the type in question. The above rather specific description of one form of the present invention is given solely by way of illustration, and is not intended, in any manner whatsoever, in a limiting sense. Obviously, the invention can assume many different physical forms, and is susceptible of numerous modifications, and all such forms and modifications are intended to be included in this application, as come within the scope of the appended claims.

I-iavingdescribed my claim:-

1. In classification yards, in combination, a stretch of track including a track'brake and a turn-out switch spaced from each other, a

invention, I now tween..- said ibrakexand; sw tch-n so rce. ;of ale ternatin cu en connected to-sa dt ack: sec ionc tr ck..:r,el ysconn cted;acros zsa d'irai ai-rec i-fi connected-tomes: aid-railsand-said r lay. 11a, sewch .im chin i-f topera ingizsaid witch; and-sari .aener izine circuit :fcr sai-dvm chine ontrollednbynsaid track :rrelav ;;3. ;In li-classification' zyards, in combination, a stretchmfitmck, agtrackibrake ;.in said track, a ggtur-n -e. ut;- switchin said trackand, spaced" from said brake, ;-a ---:detector track :section including the -.-'rails ibetween said brake-l 12,115. vswitch, a source of alternating current. connected .1110 said track section, .a tracknrelayiconnectedracross said grails, Na 1 rectifier, connected between said rails and --:said relay, 4 a 1 switch machine for.- .operat'mg said switch, 51 and energizing circuits for energizing said .=maehine. in normal and reverse directions both; controlled izby .iSZtid -;track relay;

said machinein normal Land r reverse directions both controllediby :said": track irelay, =a -'control lever movable to complete said normal and -re versecircuits for sand switch-machine when said track relay; is :pickeduup, and- -means preventing movement -:of said lever duringoperationi o'i' 'said."

switch machine;

'5 A; "classification yards, 1 in combination, a

stretch of atrack including '-a track brake and a;

turn-out switch space-d from:each-other,--adeteeter 1171"&Gk .sectioni including the rails between saidybrake :andswitch, 'a source of alternating current connectedto said-track section atrack relay-connected l across said railsg'a "relatively high resistance and. .a rectifier conn'ected betweenasaidrails and -sai'd relay, a -translating device for operating; said :swit'ch and a control circuit'tforasaid device controlled by said tr'ack 5. In classification yards, in combination, a stretch of track, a track brake in said track, a turn-out switch in said track and spaced from said brake. a detector track section including the rails between said brake and switch, a source of alternating current connected to said track section, a track relay connected across said rails, a relatively high current limiting means and a rectifier connected between said rails and said relay, a switch machine for opcrating said switch, and energizing circuits for energizing said machine in normal and reverse directions both controlled by said track relay.

6. In combination, a stretch of track, a track switch, a switch machine for operating the track switch, a detector track section, a track relay connected across the rails of the track section, a source of energy for the switch machine, and

' a stick circuit for the track relay which includes connectedacross the rails of the track section,-

a source of energy for the switch machine, and a stick circuit for the track relay which includes said source of energy, a lever for controlling the switchinachine, and an electrically operated latch for the lever included in said stick circuit.

8. In combination, a stretch of track, a track switch, a switch machine for operating the track switch, a detector track section, a track relay connected across the rails of the track section, a source of energy for the switch machine, and a stick circuit for the track relay which includes said source of energy, a lever for con' trolling the switch machine, and anelectrically operatedv latch for the lever, arranged to lock the lever in'normal or in reversezposition when energized, included in said stick circuit.

9.-In combination, a stretch of track, a track switch, a switch machine for operating the track switch, a lever for controllingthe' switch ma chine, a. latch for locking the lever when energized, a source of energy .forthe switch ma-v chine, and an energizing circuit .for the latch which includes the said source .of energy and when once closed-cannot be opened by move ment of the lever. A

10. In asystem for use on railroads and .the like, incombination, a track brakeand a turn out switch spaced from each .other, a detectortrack circuit between the brake: and switch and including a source of alternating current and a track-relay, an asymmetric unit connected between the source and the relay, 2, translating device for operating the switch, and'an energizing circuit for thedevice controlledby thetrack relay.

11. A track switch,',.-a switch machine forop crating the switch, a lever movable to either.

of two positions to control theswitch machine, a latch for locking the lever in either of the two positions against all movement, and means for releasing the latch only if .the. switchmachine has completed .its strokep,

12. A track switch, a switch machine forop crating the switch, a lever movable to either of two positions to control the'switch machine,

a latch for locking the lever in either of the two positions, a source of energy'ior the switch ma- .chine for operating it to either of two extreme positionsand arranged to prevent making .the' latchineffectiveso long as the switchmachin is not in an extreme position.

' 13/I1if0mbinatiori with a' track switch and switch 'machine for operatingthe same, a de-' tector tracki 'circuit adjacent the'switch and including a track relay, a lever, having twopositions only,- for controlling the switch machine, to-each of two extreme positions, a latch for locking the lever in each of its two positions and controlled by said relay, and a source of energy arranged to make the latch effective except when the switch machine is in an extreme position; 14. In*-cornbination with a track switch and switch machine for operating the same,-a-de tector track circuit adjacent the switch and including a track relay, a lever, having two-positions only, for controlling the switch machine to each oi two extreme positions, a latch for look ing the lever in 1 each of its two positions, a source of energy arranged to -make' the latch efiective' except when'the switch machine is in an extreme position, subject to control by the trackrelay, and stick means on the track relay energized from said source of energy. 15. In combinationwith a track switch and switch machinefor operating the same, a .de- 109 tector track :circuit .adjacent the switch and including a track relay,:a lever, having two posi-- tions only,.fo'1" controlling .the.switch machine, to each of two extreme positions, a latch for locking the lever in each'of its two positions, a source of energy arranged to make the.latch-ef-. festive exceptwhenthe switch machine is in an extreme position,'subject to control by the track relay, and stick means on the track relay ener-v gized from. said sourceof energy, the switch 11 machine being energized ifrom saidxsource of energy. Y .16. In combination-wither :track switch and,

' switch machine'ior operating the same, a. lever,

having two positions only, for controlling the -5 switch .machine, to each of t two extreme positions, 2. latchforlocking the lever in each'of its two positions, and a source of energy arranged to make thelatch effective except when the switch'm'achineis in an extreme position. 12g.

NED 1c. L. BROWN."

I use: 

